Embedded magnetic sensing for soft actuators

Abstract

A magnetic sensing approach for determining a positioning characteristic of a soft robotic actuator. A magnetic field or a change in magnetic field of a magnetic member may be measured as it undergoes concurrent displacement with a soft actuator. Additionally, an example rolling robotic wheel is illustrated. The robotic wheel may utilize magnetic sensing as described herein.

What is claimed is: 
     
       1. A system for sensing actuation of a soft robotic actuator, comprising:
 an electrostatic soft actuator comprising a flexible actuator body that is actuatable upon application of a drive voltage to the electrostatic soft actuator; 
 a magnetometer disposed relative to the electrostatic soft actuator for measurement of a magnetic field within a task space of the electrostatic soft actuator; 
 a magnetic member disposed relative to the electrostatic soft actuator to undergo a displacement within the task space upon displacement of the electrostatic soft actuator within the task space to affect the magnetic field, wherein the magnetometer is disposed on a first side of the electrostatic soft actuator and the magnetic member is disposed at a second side of the electrostatic soft actuator opposite the first side, wherein the magnetic member comprises at least at least a portion of a flexible portion of the electrostatic soft actuator; and 
 a control module in operative communication with the magnetometer, wherein the control module is operative to generate a position characterization of the electrostatic soft actuator in response to the measurement of the magnetic field upon the displacement of the magnetic member within the task space. 
 
     
     
       2. The system of  claim 1 , wherein the electrostatic soft actuator comprises a dielectric elastomer actuator (DEA) comprising an electrode pair separated by an elastomer dielectric. 
     
     
       3. The system of  claim 1 , wherein the electrostatic soft actuator comprises a hydraulically amplified self-healing electrostatic (HASEL) actuator. 
     
     
       4. The system of  claim 1 , wherein the electrostatic soft actuator comprises a folded HASEL actuator that is actuatable linearly. 
     
     
       5. The system of  claim 1 , wherein the magnetic member comprises an elastomeric magnetic material. 
     
     
       6. The system of  claim 5 , wherein the elastomeric magnetic material comprises a base elastomer in which magnetic particles are disposed that are polarized to produce a magnetic field emanating from the elastomeric magnetic material. 
     
     
       7. The system of  claim 1 , wherein the position characterization comprises at least one of a magnitude of linear displacement, a direction of linear displacement, an angle measure, a proximity indication, or an amount of curvature. 
     
     
       8. The system of  claim 1 , wherein the control module comprises a mapping that correlates the measurement of the magnetic field to the position characterization. 
     
     
       9. The system of  claim 1 , wherein the displacement of the electrostatic soft actuator within the task space is in response to actuation of the electrostatic soft actuator. 
     
     
       10. The system of  claim 1 , wherein the displacement of the electrostatic soft actuator within the task space is in response to an external force acting on the electrostatic soft actuator. 
     
     
       11. A method for sensing actuation of a soft robotic actuator, comprising:
 measuring a magnetic field within a task space of an electrostatic soft actuator using a magnetometer, wherein a magnetic member disposed relative to the electrostatic soft actuator undergoes a displacement within the task space to affect the magnetic field within the task space, wherein the magnetometer is disposed on a first side of the electrostatic soft actuator and the magnetic member is disposed at a second side of the electrostatic soft actuator opposite the first side, wherein the magnetic member comprises at least a portion of a flexible portion of the electrostatic soft actuator; and 
 generating a position characterization of the electrostatic soft actuator in response to the measuring of the magnetic field upon the displacement of the magnetic member within the task space. 
 
     
     
       12. The method of  claim 11 , wherein the electrostatic soft actuator comprises a hydraulically amplified self-healing electrostatic (HASEL) actuator. 
     
     
       13. The method of  claim 12 , wherein the electrostatic soft actuator comprise a folded HASEL actuator that is actuatable linearly. 
     
     
       14. The method of  claim 11 , wherein the electrostatic soft actuator includes an elastomeric magnetic material, the elastomeric magnetic material comprising a base elastomer in which magnetic particles are disposed that are polarized to produce a magnetic field emanating from the elastomeric magnetic material. 
     
     
       15. The method of  claim 11 , wherein the position characterization comprises at least one of a magnitude of linear displacement, a direction of linear displacement, an angle measure, a proximity indication, or an amount of curvature. 
     
     
       16. The method of  claim 11 , further comprising:
 mapping the measurement of the magnetic field to the position characterization. 
 
     
     
       17. The method of  claim 11 , further comprising:
 applying a drive voltage to the electrostatic soft actuator comprising a flexible actuator body to actuate the electrostatic soft actuator; and 
 wherein the displacement of the electrostatic soft actuator within the task space is in response to the actuation of the electrostatic soft actuator. 
 
     
     
       18. The method of  claim 11 , further comprising:
 receiving an external force acting on the electrostatic soft actuator; and 
 wherein the displacement of the electrostatic soft actuator within the task space is in response to the external force acting on the electrostatic soft actuator.